Many different tasks may be performed in a wellbore. For example, perforating guns may be shot to create perforations in a target formation in order to produce well fluids to the surface; different zones in a wellbore may be sealed with packers; plugs may be set at desired depths to isolate portions of a wellbore; a casing patch may be activated to patch openings in a casing or other type of liner; or sand screens may be installed to control production of sand. In addition to completion equipment, other tools for use in wellbores may include drilling equipment, logging equipment, and so forth.
The tools for performing these various operations may include many different types of elements. For example, the tools may include explosives, sealing elements, expandable elements, tubings, casings, and so forth. Operation, translation, actuation, or even enlargement of such elements may be accomplished in a number of different ways. For example, mechanisms that are electrically triggered, fluid pressure triggered, mechanically triggered, thermally triggered, chemically triggered, and explosively triggered may be employed.
Mechanical and hydraulic systems have been implemented in the past, however, the major disadvantages to these type of systems include complexity, moving parts, dependability of actuation, the need for intervention (mechanical shifting) and the individual vendor application (non-interchangeability).
Although improvements in downhole technology have been implemented for operating, translating, actuating, or performing other tasks with downhole elements, a need continues to exist for further improvements in such mechanisms. In particular, a simple easy method for isolating flow within a wellbore is needed, wherein the flow shut off mechanism can be passively removed, e.g., without retrieval or other complex methods of removal.